1. < Osteoporosis & Bone Health
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DEXA machines are not all the same!

Posted by njx58 @njx58, Sep 16 6:09pm

I had heard this, and AI confirms:

Numerical Differences: Hologic DXA scanners typically measure lower Bone Mineral Density (BMD) and T-scores than GE Lunar DXA systems at major sites like the lumbar spine and femoral neck.

Clinical Impact: Because Hologic readings trend lower, studies show that up to 50% of patients diagnosed with osteoporosis on a Hologic machine may fall into a different diagnostic or fracture-risk category if scanned on a Lunar device.

Tracking Progress: You cannot reliably compare serial T-scores or BMD changes over time if you switch between a Hologic and a Lunar machine. Cross-calibration formulas exist, but consistency at the same facility using the same machine brand is crucial.

Interested in more discussions like this? Go to the Osteoporosis & Bone Health Support Group.

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john78109 | @john78109 | 2 days ago

I had a DEXA scan while on Prolia at a local facility with steadily increasing scores but switched to a different site for the 2-year f/u early this year. The bone density values, suggested an unexpected drop in the t-scores. I was placed on Tymlos as a result and will have my repeat DEXA performed after 1-year of this treatment at the site of the previous scan. Thanks for addressing this possible variable.

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boneoptimist | @boneoptimist | 2 days ago
In reply to @pennyskip "My doctors say a T-score of -2.5 means I must take medication. I started heavy weightlifting..." + (show)
Profile picture for pennyskip @pennyskip

My doctors say a T-score of -2.5 means I must take medication. I started heavy weightlifting in April. My June DEXA showed a change from -2.4, where I had been for years, to -2.5. I’d been osteopenic for at least five years, yet no doctor ever mentioned lifestyle changes or the importance of preventing further bone loss. When I asked why no one raised concerns when I was at -2.4, my doctor said she had recommended weight-bearing exercise. I honestly don’t remember that or being warned about fracture risks. I wish someone had made the urgency clear years ago. But now I am questioning why go on a bone med when it is just such a slight difference? Earlier this year before diagnosis I started the weightlifting, stopped drinking alcohol (I was drinking way to much wine) and after the dexa I am now making sure I get in my protein. Going to discuss seeing where I am next April after the year of lifestyle changes versus starting Reclast right now.

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@pennyskip , lol, I had the same discussion with my current Dr about being told by a previous Dr about osteopenia in my 40's and the previous Dr just kinda shrugged and said , "this happens as you get older, take calcium". End of discussion.

As I've mentioned before, I do a dexa with TBS every 6 months because I don't want to wait 2 years and then be told that things haven't changed or have gotten worse, and I wasted 2 years to learn this when I could have tweaked things along the way. I self-pay at a freestanding outpatient clinic owned by the hospital network, same machine and technician every time. It costs me $68 self-pay (DO NOT do this AT the hospital, the cost there is much higher-mine would have been $960). Do not let them run it past your insurance first because it will cost you more that way. You have to insist on self-pay from the start, and have them note it down somewhere in your file. My Dr gives me the script every 6 months because she knows I'm all in on the nutrition, exercise, lifestyle changes, and I've had really good results so far. I know that bone changes slowly, and I don't get freaked out by a small positive or negative change in one area, but the overall trajectory has been steady improvement.

I too held out without meds for the first 19 months. Three Dexa scans over that time show I was able to improve both Tscores and BMD on my own, but it wasn't as fast as the Dr wanted and femoral neck was unchanging, so I started Tymlos. If I had been younger (I'm 63), I would have tried on my own longer.

I just read the latest recommendations saying that if we are trying to build bone and muscle at our age, we should be eating 1 gram of protein per POUND of body weight. OMG, I still can't get up to the previous recommendations on most days.

REPLY
1 reply
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ldusselier | @ldusselier | 1 day ago

What kind of machines are used at Mayo for Dexa scan?

REPLY
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jozer | @jozer | 1 day ago
In reply to @boneoptimist "@pennyskip , lol, I had the same discussion with my current Dr about being told by..." + (show)
Profile picture for boneoptimist @boneoptimist

@pennyskip , lol, I had the same discussion with my current Dr about being told by a previous Dr about osteopenia in my 40's and the previous Dr just kinda shrugged and said , "this happens as you get older, take calcium". End of discussion.

As I've mentioned before, I do a dexa with TBS every 6 months because I don't want to wait 2 years and then be told that things haven't changed or have gotten worse, and I wasted 2 years to learn this when I could have tweaked things along the way. I self-pay at a freestanding outpatient clinic owned by the hospital network, same machine and technician every time. It costs me $68 self-pay (DO NOT do this AT the hospital, the cost there is much higher-mine would have been $960). Do not let them run it past your insurance first because it will cost you more that way. You have to insist on self-pay from the start, and have them note it down somewhere in your file. My Dr gives me the script every 6 months because she knows I'm all in on the nutrition, exercise, lifestyle changes, and I've had really good results so far. I know that bone changes slowly, and I don't get freaked out by a small positive or negative change in one area, but the overall trajectory has been steady improvement.

I too held out without meds for the first 19 months. Three Dexa scans over that time show I was able to improve both Tscores and BMD on my own, but it wasn't as fast as the Dr wanted and femoral neck was unchanging, so I started Tymlos. If I had been younger (I'm 63), I would have tried on my own longer.

I just read the latest recommendations saying that if we are trying to build bone and muscle at our age, we should be eating 1 gram of protein per POUND of body weight. OMG, I still can't get up to the previous recommendations on most days.

Jump to this post

@boneoptimist I don't get up to the protein amount either; and I eat meat, eggs, cheeses at every meal; snack on nuts most days. Protein powders are gross IMO, and the one time I tried I had severe digestive problems (politely put!). Plus, with all the extra calories of all that protein I think I would gain weight, also not healthy. And too much protein can be problematic on other organs systems.

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